Only a few years ago, anyone who suggested growing plants on a roof might have been dismissed as a complete crank. Not any more.

Sedum on roofThe Botanical Roof Garden, Augustenborg, Sweden

Green roofs have started to appear on new buildings up and down the country with remarkable speed. Most feature a thin layer of the amazingly resilient hardy succulent plant, the sedum. Several different kinds are used, with leaves in a variety of different colours: yellow, green, red and bronze.

Grass and turf roofs are still not that common in this country. It’s a different story in Scandinavia, which has a long tradition of using turf, not least because it makes perfect practical sense: the layer of soil and grass insulates against cold winter weather, and protects the roof from wind damage.